1. Field of the Invention
This application relates generally to assembly line food production machinery and, more particularly, to rounding machines for rounding rough dough portions discharged from a divider into dough balls used to make products like flour tortillas, buns, rolls, etc.
2. Description of the Related Art
The industry has designed many different kinds of machines to make dough balls for producing products like flour tortillas, buns, rolls, etc. The task generally involves two successive operations: (1) dividing a large mass of dough into precise volumetrically sized dough portions or rough dough units; and (2) rounding the rough dough units into balls.
When the two tasks are accomplished by the same machine, it is sometimes called a “divider/rounder” machine, or simply a divider/rounder. When the dividing and rounding are accomplished by using separate, physically and visually distinct machines, as one would guess the two machines are often called a “divider” and a “rounder,” and together they form a divider/rounder system. Regardless of the configuration or name given, the ultimate goal of a divider/rounder machine or divider/rounder system is the creation of round dough balls that contain a very precise amount of dough by volume and weight.
Dividers
There are many different types of dividers. Two that are often used in the assembly line production of tortillas are piston-type dividers and extrusion-type dividers.
Piston-type dividers have been known for some time. In a high speed production environment, the divider has a plurality of pistons and the pistons are usually located in a rotating drum assembly that is located at the bottom of a hopper containing a mass of dough. The rotating drum assembly has a chambered area that contains a row of piston/cylinders pairs that divide dough portions from the mass of dough held within the hopper. The divider operates by rotating the drum assembly until its chambered area is in contact with the mass of dough, drawing dough into the cylinders by moving the pistons inward, rotating the drum to move the chambered area away from the hopper to a discharge area, and then moving the pistons outward to expel rough units of dough from the cylinders. U.S. Pat. No. 2,858,775, U.S. Pat. No. 4,338,341 and U.S. Pat. No. 4,668,174 are examples of piston-type dividers, and are hereby incorporated by reference.
Extrusion-type dividers are also well known. In a typical extrusion-type divider, a mass of dough is extruded into a plurality of streams and, as the extruded streams of dough flow forward, they are cut into rough units of dough by a suitable cutting mechanism, e.g. a blade that reciprocates back and forth, or a wire that is held taut within a frame that rotates round and round. U.S. Pat. No. 4,948,611, U.S. Pat. No. 4,960,601, and U.S. Pat. No. 5,110,610 are examples extrusion-type dividers, and are hereby incorporated by reference.
Rounders
There are also many types of rounders that are an integral part of the various prior art divider/rounders, or are provided separately and used in close association with the prior art dividers.
One earlier approach to rounding an array of rough dough units located on an indexed conveyor belt that stops and starts involved the lowering of a frame carrying a corresponding array of hemispherical cups over the dough units while the belt is stopped, rapidly moving the array of cups in a horizontally circular motion to mould the dough units into dough balls, and then lifting the array of cups upward so that the conveyor could move dough balls further downstream. The conveyor belt and array of cups collectively formed a rounding table.
Another common approach to rounding that works with a continuously moving conveyor belt, rather than an indexed conveyor, involves a rounding bar that is held at a slight angle just above the continuously moving conveyor belt. In a large quantity production environment that deals with a plurality of rough dough units that are simultaneously created and advanced together, in parallel, the rounder has a corresponding plurality of rounding bars, one rounding bar per rough unit of dough, that are also arranged in parallel. The rounding bars and conveyor belt also form a rounding table. In operation, the dough portions are advanced forward on the conveyor of the rounding table and, when they come into contact with a corresponding rounding bar, are rolled against the rounding bar due to the relative movement of the conveyor belt and rotated into the shape of a ball. U.S. Pat. Nos. 2,858,775; 3,311,068; 3,448,697; 4,008,025; 4,306,850; 4,338,341; 4,391,576; 4,668,174; 4,948,611; 5,110,610; 5,264,232; 5,270,070; 5,356,652; 5,714,178; 5,750,169; 5,786,016; 6,159,517; and 6,303,168 are examples rounding bars, and are hereby incorporated by reference.
Exemplary Tortilla Production Environment
In the mass production of pressed flour tortillas, the divider/rounder system makes the rough dough units and then forms them into dough balls, in parallel, in order to continuously create row after row of dough balls (e.g. 4, 6, 8, 9, or 10-across). The dough balls are moved forward, still in rows, to downstream equipment that continues to process them into tortillas. The typical equipment includes a dough relaxation conveyor called “proofer”, a tortilla press, an oven, a cooling conveyor, a stacking station, and a packaging station.
The tortilla press compresses the dough balls into thin tortillas of relative large diameter when compared to the original diameter of the dough balls. As a result, non-spherical dough balls results in non-circular tortillas and a general lack of uniformity from tortilla to tortilla. Unfortunately, rounding bars tend to form somewhat egg-shaped dough balls.
In addition, due to the consecutive pieces of equipment, a production tortilla line can require a great deal of floor space. Unfortunately, a rounder that uses rounding bars tends to consume a fair amount of that horizontal floor space.
There remains a need, therefore, for an improved dough rounder that receives rough dough units from a divider and quickly and efficiently produces a plurality of very round dough balls, in parallel, and in a quick and space-efficient manner.